Process for producing geothermal power, selective removal of silica and iron from brines, and improved injectivity of treated brines

Abstract

This invention relates to a method for producing geothermal power using geothermal brines while producing a reduced silica and iron brine having improved injectivity. The resulting compositions include a composition with reduced silica, iron, and lithium having reduced quantity of total suspended solids.

1 - 26 . (canceled) 
     
     
         27 . A process for recovering lithium from a brine, the process comprising:
 providing a treated brine comprising lithium to a column for capturing lithium from the treated brine;   contacting the treated brine with an extraction material in the column to selectively capture lithium to produce a lithium complex;   passing water through the column to produce a lithium-rich stream comprising the lithium complex, wherein the lithium-rich stream comprises a higher concentration of lithium than the treated brine; and   recovering lithium from the lithium-rich stream.   
     
     
         28 . The process of  claim 27 , wherein recovering lithium from the lithium-rich stream comprises supplying the lithium-rich stream to a filter to separate solids. 
     
     
         29 . The process of  claim 27 , wherein the extraction material comprises a granulated sorbent based on lithium alumina hydroxide. 
     
     
         30 . The process of  claim 27 , wherein providing the treated brine comprises flashing a brine to precipitate silica to produce a flashed brine comprising a reduced concentration of silica. 
     
     
         31 . The process of  claim 30 , further comprising separating precipitated silica from the flashed brine. 
     
     
         32 . The process of  claim 27 , further comprising oxidizing the brine to produce precipitates comprising at least one of magnesium, iron, and manganese. 
     
     
         33 . The process of  claim 27 , further comprising acidifying the lithium-rich stream with a salt prior to recovering lithium. 
     
     
         34 . The process of  claim 33 , wherein the salt is aluminum chloride. 
     
     
         35 . The process of  claim 33 , further comprising adjusting a pH of the lithium-rich stream to a range from 4 to 6. 
     
     
         36 . The process of  claim 27 , wherein the lithium complex is lithium chloride.